Safety device for point-switches



L. DUNN.

SAFETY DEVICE FOR POINT SWITCHES.

APPLICATION HLED AuGJ. 1918.

2 SHEEIS-SHEET I.

llyVENT'Ol? 'LO /5 DU N (waif Patented July 13, 1920.

L. DUNN. SAFETY DEVICE FOR POINT SWITCHES.

APPLICATION FILED AUG-71 1918.

2 SHEEISSHEET 2.

Patenfed July 13, 1920.

flTT'ORNEYS LOUIS DUNN, OF ST. PAUL, MINNESOTA.

SAFETY DEVICE FOR POINT-SWITCHES.

nsaasor.

Specification of Letters Patent.

Application filed August 7, 1818. Serial No. 248,733.

To all whom it may concern lie it known that 1, Louis DUNN, a citizen of the United States, resident of St. Paul, county of Ramsey, State of Minnesota, have invented certain new and useful improvements in Safety Devices for Point- Switches, of which the following is a speci- :fication.

The object of my present invention is to provide a means to cooperate with the safety device shown and described in Letters Patent of the UnitedStates, No. 867,709, issued to me October 8, 1907, so that when a train is going onto a siding from the main line it will be impossible for the switch points to shift or move until the last truck of the train has passed over the points and thereby all danger of derailing a train or a portion of it through the premature movement of the switch will be entirely eliminated.

Other objects of the invention will appear from the following detailed description.

The invention consists generally in various constructions and combinations, all as hereinafter described and particularly pointed out in the claims.

In the accompanying drawings forming part of this specification,

Figure 1 is a plan viewof a section of a railroad track and a point switch and op erating mechanism therefor.

Fig. 2 is a sectional view on the line wm of Fig. 1,

Fig. 3 is a sectional view on the line y-g of Fig. 1,

Fig. l-jisa sectional view corresponding to Fig. 3, but in a reverse position.

in the drawing, 2 and 3 represent the rails of the main track and 4t. and 5 the rails of the side track. 6 and 7 are the switch points for directing the train from the main to the side track. A. rod 8 connects the points for simultaneous movement and a spring device 9 normally tends to hold the points away from the main rail 2 and against the stop device 10. A switch standard 11 is mounted on a base 12 at one side of the track and is provided with a lever 13 mounted to swing vertically and enter notches 14 provided in the top of the standard for locking the switch in its different positions. At one end of its stroke it drops into one notch for locking the switch for the main line. At the other end of its movement it drops into another slot when the switch is set for the siding and between these two points there is no intermediate or neutral position in which the points are withdrawn from contact with both rails. A link 15 connects the switch standard with a loop 16 on a lever 17 that is pivoted at 18 011 a tie and engages a loop 19 that is pivotally connected with the rod 8 so that when the link 15 is operated by the movement of the switch lever, the points will be moved back and forth toward or from the track rails. A shaft 20 is mounted in bearings 21 on the ties and has a crank at one end connected bya link 22 with the loop 19.

Mounted on the shaft 20 are cranks 23 connected by links 2 1 with a bar 25 carried by arms 26 which are pivoted at 27 and have a movement toward and from the track rail 2 for the purpose of moving the bar 25 into contact with said rail or withdrawing it therefrom. An arm 28 on the shaft 20 is provided with a weight 29 which normally tends to hold the bar 25 in its retracted position, as indicated in Fig. 4. Then, however, the switch points are set for the siding, the bar .25 will be moved up against the track rail and in this position will be held by the wheels of the trucks passing there over until the last truck has passed the switch, the end of the bar 25 lapping by the switch points, as shown in Fig. 1, so

that each wheel passing over the rail 2 will have cleared the switch before it passes out of contact with the end of the bar 25.

When the bar 25 is moved to the position indicated in Fig. 3, it will be beneath the wheels of the truck passing over the rail, and will be held in the position shown by the wheels. The wheels need not bear on the bar, but will overhang it sufficiently to prevent the bar from swinging to the position shown in Fig. 1 until the wheels of the truckhave passed the switch point. This bar 25, as shown in Fig. 1, is of sufficient length to bridge the space between the forward and rear trucks of the car and consequently there will be no possibility of the bar swinging away from the track rail until all the trucks of the train have safely passed the switch.

For the purpose of automatically shifting the switch from the siding to the main line, I provide a trip lever 30 pivoted at 31 and projecting into the path of a wheel flange to be actuated thereby and moved horizontally on its vertical pivot. A link 32 connects the lever 30 with a bell crank 33 Patented July 13,1920.

which in turn is connected by a rod 34 with a bell crank 35 near the switch standard. A flexible connection 36 is provided between the bell crank 35 and a vertical lever 37 hinged to the base of the switch stand, the parts being normally held in the positlon i shown in Figgl by a spring 37. When the switch lever is moved to set the points for the siding, the shaft 20 will be rocked and the cranks 23 raised and the bar 25 seated against the side of the rail 2 and the train approaching the switch will pass over the points onto the siding, the trucks riding on the bar 25 and holdin it and the switch points in position to direct the train onto the siding. In the meantime, however, the

foremost truck of the train has engaged the leverand released the switch lever, al-

lowing ,it to swing to the full line neutral position shown in Fig. lassoon as the last truck'has' passed off the 'bar '25 and has cleared the switch. r

When the switch lever 13 is moved to set the switch for the siding and turned down into one of the notches lat which will be in front of the upright lever 37 (see Fig. 2)

so that when the bell crank is rocked to pull the flexible connection 36 and swing.

. the lever 37 outwardly, it will lift the switch itjcan swing. to the neutral position, or, as

lever and disengage it from its notch so that shown in Fig. 1. It will swing to this positio'n'as soon as the last truck has passed offthe bar 25 and cleared the switch points when this has been done, the switch will be automatically. opened to the mainline and if another train follows the one entering the V "siding, it will be directed past the points 6 V and 7 in their neutral position and through rails, of the movable switch points, a switch lever operatively connected with-said switch polnts, mechanism for automatically throwing the switch points to a neutral p0sitlOll when the train passes onto the siding, and means for preventing the movement of:

the switch points until the last truck has passed from the mamtrack' ra ls to the sldmg, said means including a bar, rocking arms whereon said bar is mounted for moving it toward or from the path of the car wheels, a shaft, cranks mounted thereon, and links connecting said cranks with said arms. 7

2. The combinatioi'nwith the main track rails, of the movable switch points, a switch lever operatively connected with said switch points, mechanism for automatically throwing the switch points to a neutral position when the train passes on to the siding, a bar mounted to lap by the ends of the switch points and be moved into the .path'of the truck wheels to be held thereby and prevent the movement of the switch points to a neutral position until the last truck has passed over said pointspivoted arms whereon said bar is mounted, a shaft and cranks therefor, and means connecti-ng saidcranks with said arms.

The combination with the main track rails, of the movable switch points, a switch lever operatively connected with said switch points, mechanism for automatically moving said switch points to a neutral position, a bar mounted to be seated against one of the main track rails when the switch: points are. set for the siding, the engagementof the truck wheels with said bar preventing the movementof the switch points to a neutral position until the 'last'truck has passed over said points a rock shaft, cranks mounted thereon, means connecting'said cranks with said bar and a weight carried by said shaft normally tending to hold said bar in a retracted position out of the path of the truck wheels.

4. The"combinationfwith the main track rails, of the movable switch points, a switch lever operatively connected with said switch points, mechanism for automatically throwing the switch points to a neutralposition. when the train passes on to the siding,arms pivoted near the track rails, a bar carried by said arms and adapted to swing into contact with the track rail and in the path of the truck wheels, links pivotally con nected to said arms intermediate. to said bar and the pivots of saidarms, means for oscillating said arms to swing the pivots of said links thereon past the center of the pivots of said arms, and means fornormally holding said arms in such position.

In witness whereof I have hereunto set my 1 hand this 24th day of July, 1918.

" LOUIS DUNN. 

